Non-Hodgkin lymphoma

What is non-Hodgkin lymphoma?

Non-Hodgkin lymphoma (formerly known as non-Hodgkin's lymphoma) is cancer of the lymphocyte - a type of white blood cell produced in the bone marrow, which travels in the blood to other parts of the body, normally the lymph glands. The lymph cells in these areas become malignant. Cells are programmed similarly to computer software. Lymph cells become malignant by losing the part of their cell program that teaches them how to grow and mature to carry out their function.

Lymphoma happens when the 'programme' inside a lymph cell becomes faulty and the growth and multiplication of the cells is no longer controlled or they fail to reach full maturity.

Lymph gland tumours normally occur as enlarged lymph glands that can be felt or occasionally seen on X-rays of the chest or stomach. Most lymph gland enlargements are due to infection rather than malignant lymphoma and will resolve themselves.

Occasionally, lymph gland enlargements may occur as the result of the spread of cancer from other sites in the body, such as the breast, bowel or lung.

While enlarged lymph glands are the most common symptom there is lymph tissue in all body organs and lymphoma may occasionally occur in other parts of the body such as the liver, lung or brain. Some lymph gland tumours spread back to the bone marrow to involve this organ in the disease.

Causes

There is no known single, or specific, cause of lymphoma. The risk increases slightly in some patients with chronic infections, autoimmune diseases such as coeliac disease, or rheumatoid diseases such as rheumatoid arthritis. People who have received long courses of chemotherapy for other diseases may also have increased risk of lymphoma.

Immuno-deficiency or deficiency of the immune system which has been inherited, or caused by viruses such as the AIDS virus, is also a risk factor in developing lymphoma. However, apart from highly-specialised circumstances, there is no specific infectious cause and there are no known substances that cause lymphoma.

Diagnosis

If lymphoma is suspected a blood test will be carried out to check for any abnormalities. This test might indicate an underlying malignant (cancerous) blood disease. It also gives a blood cell count and is useful for providing information on the likely behaviour of the lymphoma as well as how the kidneys and liver are functioning.

Diagnosis is confirmed following a biopsy, which removes a lymph gland so the organisation and structure of the cells can be studied. A combination of the individual cell appearance, the structure of the lymph gland and additional information from a number of other studies will show whether a lymphoma is present and whether it is low, intermediate or high grade.

The lymphoma may occupy only one area in the body (stage 1) or it may have spread throughout the body (up to stage 4). The person's age, general medical condition and whether the lymphoma is low, intermediate or high grade will all have an affect on the prognosis. Staging is the final step in determining the appropriate treatment plan but often a second series of tests are carried out before this happens.

Testing can take a number of forms and includes:
* Additional blood tests
* A lumbar puncture - fluid is taken from the spine to test whether the lymphoma involves the brain or spine.
* A CT scan (computerised axial tomography) - a painless radiology procedure where pictures of the chest, abdomen and other parts of the body are fed into a computer to show a detailed view of the body. A special liquid may be given before the test to help outline the abdomen and occasionally injections are given into a vein to outline different organs. People usually lie on their back for about ten minutes during the scan.

Treatment

Some types of lymphoma grow very slowly and do not need treating for a long time, if at all. Treatment for each person is determined by factors such as age, general health, type of lymphoma and whether it has spread to other parts of the body. Other factors considered include the behaviour of an enzyme in the blood called lactate dehydrogenase (LDH) and another substance in the blood called beta 2 microglobulin.

The aim of treatment is to destroy as many malignant (cancerous) cells as possible and bring the disease into remission. There are a number of treatments that can be used to do this, but the main ones are chemotherapy, radiation therapy or a stem cell or bone marrow transplant.

For more information about this disease, or a copy of our information booklet on non-Hodgkin lymphoma, please contact lbf@leukaemia.org.nz or 0800 15 10 15.